Brush, in particular toothbrush, and associated production method

ABSTRACT

A brush, in particular a toothbrush, including a head part with a cleaning structure with bristles, a handle part and a neck part, a cavity with at least one outlet opening for an active substance being located in the head or neck part. In one embodiment, the cavity incorporates an active substance element, which contains the active substance in a carrier material and releases the substance in a controlled manner when it comes into contact with water. The cavity may be adapted to the shape of an active substance element by means of defined external contours. The volume of the cavity is preferably 1-2 times and no more than 4 times greater than the volume of the active substance element, ensuring that the latter is preferably surrounded by water during use. This allows the active substance to be effectively metered and ensures the brush is easy to use.

This is a Continuation of application Ser. No. 11/662,486 filed Apr. 4,2007, which in turn is a National Stage of PCT/EP2005/009615 filed Sep.7, 2005, which claims priority to European Application No. 04022614.4filed Sep. 22, 2004. The disclosures of the prior applications arehereby incorporated by reference herein in their entirety.

The invention relates to a brush, in particular a toothbrush, as claimedin claims 1 and 2, and to an associated production method as claimed inclaim 17.

Disposable toothbrushes are known which, in various ways, alreadycontain toothpaste. In U.S. Pat. No. 5,346,324 and U.S. Pat. No.5,909,977, a very liquid toothpaste is located in a reservoir in thehandle area and is forced by a plunger into the head area, where itemerges through openings into the area of the bristles. Disadvantages ofthis are the difficult dosing of the toothpaste, the need to use veryliquid toothpaste, the unwieldy handle, the frequent drying-up andtherefore blocking of the fluid channel, and the difficult to impossiblerefilling of the reservoir.

Toothbrushes are also known in which a predetermined amount oftoothpaste is located in a cavity in the head area and is squeezed outof the head area by manual deformation before cleaning the teeth. InU.S. Pat. No. 1,947,720, deformation of the head area causes a slit-likeand initially closed aperture to break open, such that the toothpastecan emerge. Repeated use by refilling is not possible, nor is exactdosing possible. Release of the toothpaste also requires application ofconsiderable force. Similar examples in which toothpaste is squeezed outmanually are disclosed in FR 2,583,625 or U.S. Pat. No. 5,865,195. InU.S. Pat. No. 5,490,530, the outlet openings can be closed again by aslide. The toothpaste is squeezed out by pressing a button which isarranged on the underside of the head part and which decreases thevolume of the toothpaste reservoir. Exact dosing of the toothpaste isalso difficult here. Refilling of the reservoir is impossible. In U.S.Pat. No. 5,366,310, the toothpaste is located in a sealed capsule whichis pushed into the brush head. After the seal is removed, the toothpasteis released by squeezing it out manually. Although refilling is inprinciple possible in this case, exact dosing is still difficult.

In all the examples mentioned, the user has to act manually on the brushin order to release any toothpaste. Since a certain force is needed forthis, and since a certain dexterity is required for the desired dosing,the known toothbrushes are not easy to handle for everyone.

In WO 2004/021914, a disposable toothbrush contains an encapsulatedportion of liquid dentifrice in the area of the bristles. The capsule isbroken open by contact with the teeth. The problem with this, inaddition to the fact that it is limited to a single use, is that thedentifrice can emerge even when the toothbrush is not used properly. Inaddition, there is a certain risk of damage to the palate and gums atthe non-defined rupture points of the capsule.

The invention is therefore based on the object of making available abrush, in particular a toothbrush, with an active substance, which brushor toothbrush is suitable for repeated use and/or for refilling of theactive substance and permits simple handling and simple dosing of theactive substance. Moreover, a method for producing such a brush is alsoto be made available.

The object is achieved by a brush with the features of claims 1 and 2,and by a method with the features of claim 17. Advantageous developmentsare set out in the dependent claims, the description and the drawings.

In a brush, in particular a toothbrush, with a cavity which is arrangedin the head part or neck part and which has at least one outlet openingfor an active substance, said cavity according to the invention containsan active substance element which is composed of a carrier material andof an active substance bound in the latter. The carrier materialreleases the active substance in a controlled manner upon contact withwater. The carrier material is preferably solid, but can also be ahigh-viscosity paste. Preferably, it is to a large extent dimensionallystable when not in contact with water.

Alternatively, or in addition to this, the cavity is adapted to theshape of the active substance element with a defined external form. Thevolume of the cavity is greater, in particular 1-2 times greater, andnot more than 4 times greater, than the volume of the active substanceelement. The active substance can also protrude from the head in orderto form a sufficient contact surface for the release of activesubstances. This ensures that water washes sufficiently round the activesubstance element during use.

The release of the active substance takes place in a purely passive way,by means of water washing round the active substance element, and nomanual action on the brush is necessary. The brush would thereforealready release active substances if it were to be placed in water attemperatures of 15° Celsius or higher. The movement involved in cleaningthe teeth can of course additionally assist the migration of the activesubstance through the improved circulation of liquid, but the aim 1s toensure that the brush releases active substances in connection withwater without mechanical actions. The dosing can be adapted andpredetermined by suitable choice of the solubility or break-up of theactive substance element, or its ability to release the activesubstance, and the size of the outlet openings, and the dosing does nottherefore depend on the dexterity of the user.

In an advantageous development, the brush is flexible, at least in thearea of the cavity, in such a way that, when the brush is used asintended, i.e. for cleaning the teeth, the cavity deforms in such a waythat water is sucked into the cavity and forced out again. In contrastto the prior art in which a pasty composition is squeezed out by manualpressure before cleaning the teeth, the invention makes use of apump/suction effect on the water, permitted by the flexibility of thecavity. In this way, the intake of water into the cavity and thewashing-out of the active substance can be intensified without the userfirst having to manipulate the brush. The cavity is for this purposepreferably adapted to the shape of the active substance element, suchthat the latter is spaced apart at least partially from the inner walland water washes round it during use. Advantageously, the cavity is atleast partially enclosed by thin-walled boundary elements with a wallthickness of less than 3 mm, preferably of less than 1.5 mm, made ofelastomeric soft material, in order to generate said pump effect evenupon the slightest contact.

In addition to the flexible cavity, it is also possible for the entirebrush head to have flexible, movable partial areas, e.g. a flexiblefront part of the brush head. The flexible deflection of this partialarea also influences the volume of the cavity and, once again, theabove-described pump/suction effect is produced. The flexibility of thebrush head is preferably formed at the location where the cavity takesup the greatest proportion of the cross section of the brush head. Thishas the advantage that only a small proportion of the cross section ofthe head has to be made flexible. This can be done by targeted weakeningof the material, for example a film hinge, lateral tunnel, etc., in thehard component, or by means of a combination of the hard and softcomponent. It is also possible for the flexible zone to be madecompletely from soft material.

The active substance element is preferably a solid body or a highlyviscous and dimensionally stable paste, but it can also be formed by anencapsulated liquid, pasty or particulate substance with a water-solubleenvelope. By suitable choice of the solubility or break-up of the activesubstance element or of its envelope, it is possible to achieve a dosingthat is well defined and that may permit a uniform release of activesubstance throughout a teeth-cleaning procedure. In the case of a solidbody or a highly viscous paste, multiple use of the same activesubstance element is possible if the latter is dimensioned, and itssolubility or break-up chosen, such that it lasts for several typicalcleaning procedures. Depending on their intended purpose, the activesubstances are released before, during or after the teeth-cleaningprocedure. In this case, there is no danger of the openings drying upand clogging, because any residues can be easily washed away after use.

In another embodiment variant, the active substance element comprises asubstantially dimensionally stable carrier from which the activesubstance is washed out, but which maintains its original shape. Itpreferably contains an indicator by which it changes color or fades overthe period of use or in line with the number of uses.

In an advantageous development of the invention, the active substanceelement can be refilled via a recloseable insertion opening. In thisway, it is possible to complete the step from a simply designeddisposable brush to a high-quality cleaning product.

The active substances perform the following tasks for example:

-   (a) antibacterial action within the brush head-   (b) indication of the success of cleaning-   (c) introduction of cleaning substances that are not contained in    conventional cleaning agents-   (d) introduction of cleaning agents that serve as a two-component    system in combination with conventional cleaning agents-   (e) bleaching.

The brush is composed of a head part with a cleaning structure,generally bristles, and with a neck part and a handle part. All thecomponent elements can be made from at least one hard component and oneor more soft components. Examples of hard components that can be usedare polystyrene (PS), styrene-acrylo-nitrile (SAN), polyester (PET),polyethylene (PE), polymethylmethacrylate (PMMA),acryl-butadiene-styrene (ABS), etc., preferably polypropylene (PP).Examples of a soft component that can be used are an elastomericmaterial such as polyurethane (PUR) or polyethylene (PE), preferably athermoplastic elastomer (TPE or TPU). In the brush head, hardnesses ofbelow 70 Shore A are used, preferably of below 40 Shore A. The bristleregion is preferably formed at least partially with conventionalbristles, e.g. of polyamide (PA) or polyester (PBT) and, optionally,with elastomeric cleaning or massaging elements. The conventionalbristles have, for example, a cylindrical geometry with a diameter ofless than 0.25 mm, preferably of between 0.1 mm and 0.2 mm, and aregathered into bundles. The elastomeric massaging or cleaning elementsusually have greater diameters, with the smallest dimensions in thecross section of 0.5 to 5 mm, preferably 0.5 to 2 mm.

Cleaning elements, in particular bristles and/or pliable elements, arepreferably arranged in direct proximity to the outlet openings, andtheir mechanical properties, e.g. dimensions, flexibility, material, areadapted to the action that is to be achieved with the active substancethat is to be introduced. Examples in toothbrushes are

-   (a) abrasive active substances with shorter bristles for surface    cleaning (whitening effect),-   (b) antibacterial active substances for deep cleaning with longer    interdental bristles,-   (c) skincare active substances in the area of the elastomeric    massaging or cleaning elements for invigorating the gums, oral    cavity or tongue,-   (d) other combinations of active substances and corresponding    bristles.

The cavity offers space for at least one active substance element. Thecavity preferably offers additional space such that water can wash roundthe active substance element and, in this way, the active substance isable to exert its action by means of being partially or completelydissolved. To permit sufficient circulation of water in the cavity,provision is preferably made for the volume of the cavity to be designednot more than four times greater, particularly preferably one to twotimes greater, than the size (the volume in the original size) of theactive substance element. In toothbrushes, the cavity has a volume offrom 5 to 1500 mm³, preferably 100 to 500 m³.

The active substance element can be clamped laterally or vertically inthe cavity. To ensure that water is able to circulate around it to thegreatest possible extent, projections or other geometric elements arepreferably formed for this purpose in the soft and/or hard component inthe cavity. This ensures that, during the cleaning procedure, the activesubstance element cannot be struck back and forward within the cavityand cannot break apart too early. However, the active substance elementcan also protrude outward through recesses in the boundary of the cavityand can extend out of the brush head laterally or on the face supportingthe bristles.

The cavity is preferably generally designed such that the activesubstance element is positioned in a stable manner in the cavity despitethe continuous break-up. For this purpose, the cavity is provided with aflexible element which is made from soft material and which exerts akind of spring action on the active substance element, for example by anouter wall of the cavity being curved outward upon insertion of theactive substance element. The active substance element in the originalsize is fixed in the cavity with a certain pretensioning. Except for theabove-mentioned projections, the inner shape of the cavity essentiallyfollows the geometric shape of the active substance element, preferablywith a predefined distance. This preferably results in a substantiallyspherical or ellipsoid geometry of the cavity, adapted to spherical orellipsoid active substance elements. In an alternative embodimentvariant, the cavity can be designed as a slit into which a plate-shapedor film-shaped active substance element can be inserted. In anotherembodiment variant, the active substance element can be inserted in arod-shaped or cylindrical geometry into a correspondingly shaped cavity.

In a plan view of the cleaning structure, the cavity lies preferablyinside the bristle region, if conventional bristles are present. Thismeans that the cavity can be produced with a thin wall, but a sufficientnumber of bristles can still be anchored all round the cavity, with acertain anchoring depth required for technical reasons. Cleaningelements made from a soft component, which require less head volume andanchoring depth than conventional bristles, are preferably formeddirectly over the cavity. In addition, for secure anchoring,conventional bristles require the hard component. Since the cavity onthe face of the brush head supporting the bristles is preferablydelimited by a membrane of soft material, it is technically verydifficult to anchor conventional bristles in this area.

The cavity is delimited by a wall of hard and/or soft component, butpreferably at least in some areas also by soft component, since theaforementioned flexibility can easily be achieved in this way.

It is advantageous, as regards the anchoring of the bristles, if thecavity is positioned in an area which adjoins the brush head, forexample in the brush neck or in the transition between brush neck andbrush head, and which comes into contact with water. This design has theadvantage that the cavity does not have to be taken into considerationin anchoring the bristles within the brush head. The fact that theactive substance does not emerge where it generally exerts the optimumeffect, that is to say in the head area, is taken into account.

The cavity comprises at least one outlet opening for the entry of water,for the emergence of the active substance dissolved in the water, andfor washing out the cavity under a tap after use. In variants with arefill option, at least one insertion opening for insertion of theactive substance element by the user is additionally provided. Theinsertion opening, in the opened state, is larger than an outletopening. The insertion opening is preferably located on the rear face ofthe brush head, and the outlet opening on the front face of the brushhead. Alternative embodiment variants have the insertion opening on theside of the brush head. Alternatively or in addition, the outletopenings can be placed on the side and/or rear face of the brush head.

The insertion opening can preferably be reclosed. However, it can alsoserve as an outlet opening and must not completely seal off the cavity.The insertion opening can be formed by means of a cover or closure piecewhich is either removable or integrated into the head, for example bymeans of a film hinge injection-molded directly onto the head.Particularly preferably, the recloseable element is a membrane made fromsoft material and having a suitable opening which, for example,comprises one or more intersecting slits and corresponds to the size ofthe active substance element. The membrane can at the same timeconstitute a flexible wall of the cavity and/or serve as a support forcleaning/massaging elements. As an alternative to slits, other geometricelements can be provided which permit insertion of the active substanceelement and as far as possible prevent its escape, for example anexpandable hole formed in the membrane and smaller than the activesubstance element.

In the case of a membrane, the latter has a thickness of less than 3 mm,preferably a thickness of 0.7-1.5 mm. Preferably, 2 to 6 slits are usedas the insertion opening. The length of the slits is 3-15 mm, preferablyabout 6-10 mm, for toothbrushes.

The insertion opening can have a safety device which prevents the activesubstance element from falling out during use, or at least makes thisdifficult. For example, the membrane is formed with slits or a funnel insuch a way that the active substance is inserted with little pressure(e.g. 10 to 300 g), but falling out requires more pressure, by virtue,for example, of a funnel-shaped geometry in the area of the opening. Itis less preferable, but still possible, to provide additional closureelements or securing elements.

The insertion opening can still be closed at the time of the first use(tamper-evident safety means or seal). The first time the activesubstance element is inserted, the tamper-evident safety means can bebroken by the user, for example by severing thin residual connectionswithin the prefabricated slits.

The outlet openings permit a continuous but limited emergence of theactive substance dissolved in water. The number of openings and theirsize (total surface area of the outlet opening) and the water-solubilityof the active substance element or of the carrier material determine theactual emergence of the active substance dissolved or dispersed inwater. Since the water-solubility of the active substance tends torepresent a resultant parameter, the outlet openings (number and size)are adapted to the water-solubility of the active substance, in order todetermine the range of the active substance during use. In this way, thedissolving of the active substance element can also serve as a timeindicator for the (total) cleaning period that has hitherto elapsed.

An individual outlet opening is preferably not less than a minimumsurface area of 0.05 mm². This is because smaller openings can easilysoil and thus impair the exchange of liquid. In addition, it isadvantageous if the user can see through the outlet openings to assessthe amount of active substance element still remaining in the cavity andcan decide whether the active substance should be topped up. For thesereasons, surface areas of 0.05-100 mm², preferably 1-20 mm², arepreferably used for the outlet openings. This ensures precise dosing andprevents the active substance or fragments of the active substanceelement from being able to leave the cavity in an uncontrolled manner.

The individual outlet openings on a brush head can have different sizes(surface areas) in order to weight the released amount and the site ofrelease. Preferably, individual groups of outlet openings are arrangedat specific locations on the brush head. In this way, the release of theactive substances at different sites of the bristle region can becontrolled in terms of quantity and location. As has been mentionedabove, there is preferably an interplay between the active substance andthe active bristles specifically provided in combination with it. One tofive groups (clusters) of outlet openings are preferably formed. Thesegroups of outlet openings can also be positioned on the brush headasymmetrically with respect to the longitudinal axis. The differentgroups of outlet openings are preferably produced from the same materialin one operating step. Particularly if the outlet openings are formed inthe elastomeric material, this is done from one injection point for allgroups, i.e. these groups are materially connected to one another. Theoutlet openings can be designed with geometric elements that increasethe surface area in proximity to the outlet opening, in order to keepthe active substance as much as possible in the area of the brush head.For example, a substantially funnel-shaped geometry can be used, or ageometry at least opening toward the outside. This also makes it easy toclean the cavity under a tap after use. Additional cleaning andmassaging elements in the area of the outlet openings have the sameadvantage. For the same reason, however, as an alternative designelement, sponge-like or perforated, soft elements can be positioned inthe area of the outlet openings and likewise contribute to betterretention of the active substance.

The outlet openings can be formed in the hard material and/or in thesoft material of the brush head. However, they are preferably integratedinto the above-described membrane made from soft material. In this case,the latter preferably has a thickness of less than 3 mm, preferably of0.7-1.5 mm.

As has been described above, the cavity is preferably delimited by amembrane or membranes of soft material. Said membrane or membranes areflexible in order to adapt to the surrounding environment (gums, teeth,oral cavity, etc.) during use, and in order to exert a certainpump/suction effect on the cavity under the pressure exerted on themembrane by the cleaning procedure. These effects can be intensified bya curved shape of the membrane. Together with the outlet openings, themembrane can form a kind of expandable mesh structure. As has beendescribed above, this mesh structure can have minimal outlet openingswith a surface area of at least 0.05 mm². Of course, mesh structures canbe arranged on all sides of the brush head. To increase the surface areaand thus maximize the cavity, they preferably have a convex U-shaped orcup-shaped outer geometry. The crosspieces of the mesh have a diameterof 0.1-2 mm, preferably of 0.2-0.5 man, and are made from soft material(e.g. TPE or PE).

Said membrane or membranes with the openings preferably formrecognizably separate geometric elements within the brush head which arevisible to the user and which in particular are also distinguished incolor from the rest of the brush head. The user can therefore quicklysee where the active substances emerge from the brush head. In differentembodiment variants, the following geometric elements for the membranescan be used:

-   (a) The membrane or membranes with the openings are preferably    designed with a curved/ellipsoid/balloon shape. The membrane with    the outlet openings can have a mesh-like structure or simply just a    few holes. The curved membrane or membranes are preferably    positioned on the front face and rear face of the brush head, but    can also be positioned on the sides.-   (b) The membranes with the openings form a kind of flexible    concertina or bellows structure on the side or rear face of the    brush head. The peaks of the concertina structure serve as cleaning    and massaging elements.-   (c) The membranes with the openings form a kind of gill structure on    the side of the brush head. The outlet openings are formed by means    of slits in this structure.-   (d) The membranes with the openings form a kind of nipple/knob    structure preferably on the side of the brush head or rear face of    the brush head. The outlet openings are formed in a funnel shape    inside the elevations.

Moreover, cleaning and massaging elements made from soft material arepreferably formed integrally on the flexible membranes delimiting thecavity. This partial aspect of the invention, that of designing a partof the brush head with a flexible membrane and of designing the latterwith cleaning and/or massaging elements made from soft material, canadvantageously also be used for brushes that do not have a cavity foractive substances, but for example only have an empty cavity or nocavity at all. The membrane and the cleaning and/or massaging elementsare preferably produced in one operating step, particularly by theinjection-molding technique. This permits production of a brush with aparticular elastic suspension of the cleaning/massaging structure.Unless specifically relating to the cavity, the following preferreddesigns also apply to brushes without a cavity, but with a membraneprovided with a cleaning/massaging structure.

In the toothbrushes according to the invention, the fact that cleaningand/or massaging elements made from soft material are formed integrallyon a flexible membrane has the following advantages:

-   (a) The surface area in the region of the outlet openings is further    increased, such that the active substances are held as long as    possible on the brush head (retention) and permit a uniform release    during the cleaning procedure.-   (b) it is difficult, from the production point of view, to anchor    conventional bristles in a thin membrane. The pliable elements    increase the cleaning action, and thus the efficiency of the brush    head, on the face of the brush head supporting the bristles.-   (c) The flexibility of the membranes additionally increases the    cleaning action of the cleaning elements positioned on them, since    the flexibly mounted cleaning and massaging elements can better    adapt to the irregular surface of the dentition, of the oral cavity,    of the tongue or of the gums.-   (d) The cavity, which is delimited by flexible membranes, is easier    to clean (e.g. with the fingers or with a cotton bud) since the    membrane can be bent into a suitable position for cleaning.

The cleaning or massaging elements in the area of the outlet openingspreferably have a bristle-shaped, lobe-shaped, lamella-shaped ornipple-shaped geometry. These elements are preferably formed conicallyand are preferably formed from the same material as the membrane in thesame operating step. The following structures are possible, for example:

-   (a) a bristle-like structure from the node points of a mesh-like    membrane,-   (b) massage lobes, lamellas or knobs on the side of the brush head    or the rear face of the brush head, for massaging the gums, oral    cavity or tongue.

From the production point of view, it is preferable if the cleaningand/or massaging elements located in the area of the outlet openings areoriented parallel to the de-molding direction of the brush head. It ismore complicated in manufacturing terms, but more effective during use,to provide cleaning or massaging elements that are oriented at a definedangle, preferably substantially at right angles, to the curved membranesurface.

The cleaning or massaging elements located in the area of the outletopenings are preferably less long than the conventional bristles intheir proximity, with the result that, during use, a kind of reservoirfor the active substance dissolved in water can form in the end area ofthe cleaning or massaging elements.

In addition to the outlet openings of the membranes, the cleaning andmassaging elements themselves can also have outlet openings, which isthe case, for example, in straw-shaped bristles, lamellas and nippleswith holes. These have the advantage of being able to bring the activesubstance directly to the site of use. The active substance can in thiscase cover a relatively long distance by means of a capillary action.

In another possible embodiment variant, the membrane itself can releaseor allow the passage of active substances in the submicroscopic range,for example as a result of microporosity or semi-permeability.

The active substance element is preferably a solid body which at leastpartially dissolves in water during use. The active substance element inthe form of a solid body is shaped as a tablet, pill, rod-shapedelement, plate or film to match the cavity. Alternatively, and lesspreferably, it is possible to use a paste or ductile composition with adynamic viscosity higher than that of conventional and commerciallyavailable pastes (toothpastes). A spatially defined structure can thusbe produced, and the active substance can be held as long as possible inthe cavity. After its introduction into the cavity, the paste canharden, in order to release the active substance in diverseapplications.

The active substance can be easily portioned by the user. The solid bodyis already pre-portioned in the package in which it is sold. The pastecan be easily portioned by the consumer, by virtue of the predefinedvolume of the cavity.

The active substances can be used together with conventional cleaningagents or independently of these. The brush can generally also be usedwithout active substances, and with conventional cleaning agents.

The active substance element can have several phases with differentactive substances which can be released in a time sequence according totheir structure. The following alternatives are possible:

-   (a) solid body composed of several shells or layers (break-up of one    shell after another);-   (b) solid body with a liquid or particulate core, which is released    after break-up of the shell.

A distinction can be made between the following types of activesubstances which, together with a suitable carrier material, form theactive substance element:

-   (a) Toothpaste-like action, which removes the need for a    conventional toothpaste. The following ingredients are possible:    sorbitol, flavoring agents, hydrated silica, sodium lauryl sulfate,    sodium monofluorophosphate, creatine, zinc sulfate, triclosan,    glycerin, sodium saccharin, propylene glycol, disodium phosphate,    alumina, trisodium phosphate, sodium fluoride, betaine, titanium    dioxide, cellulose gum, tetrasodium pyrophosphate, etc.-   (b) Antibacterial action for occasional cleaning of the brush head    in a beaker before or after cleaning the teeth. The following    ingredients are possible: sodium bicarbonate, citric acid,    phosphoric acid, sodium carbonate, potassium carbonate, sodium    perborate, sodium hexametaphosphate, sodium benzoate, sodium    stearate, etc.-   (c) Indication of the success of cleaning by staining of the plaque    on the surface of the teeth, by means of staining of the plaque    residues. The following ingredients are possible: glucose,    maltodextrin, magnesium stearate, flavoring agent, saccharin,    microcrystalline cellulose, etc.-   (d) Auxiliary active substances which do not occur in conventional    pastes and which complement or intensify the action of said pastes.    Ingredients from (a-c).-   (e) Ingredients for bleaching, for example ingredients containing    hydrogen peroxide.-   (f) Two-component system composed of active substances and of    specially developed toothpaste. When they meet, a chemical or    physical reaction takes place. This variant is provided especially    for active substances that cannot be integrated in a paste, because    they would react directly with one another.

Examples of carrier materials that can be used are biodegradablesubstances based on starch or plastics that do not chemically react withthe active substances. A preferred carrier material is Polyox® from DowChemicals, a water-soluble synthetic resin based on polyethylene oxidepolymers, which is suitable for formation of a matrix or carrier for anactive substance and which, because of its thermoplastic properties, canalso be processed in a variety of ways, for example cast, injected orextruded.

In principle, both single use and also multiple use of an activesubstance element are possible. In single use, one application of thebrush uses up one active substance element. The active substance elementcan be inserted again before each application or can also just be usedoccasionally. In the case of multiple use, one application of the brushuses up only some of the active substance element. The user knows whenthe active substance is used up and can then refill the brush by meansof a new active substance element. It will be appreciated that theconcentration and amount of the active substance will be much lower forsingle use than for multiple use. In single use, the concentrationcorresponds approximately to the concentration of the active substancesof conventional pastes. In multiple use, the corresponding concentrationis increased by several times. In addition to the concentration, therange/period of use of the active substance element is also influencedby the water-solubility and water circulation/openings.

In single use and multiple use, the system, cavity, openings and watersolubility of the active substance element can be set such that acertain period of use can be indicated to the user (time indicator). Forexample, in single use, the properties are chosen such that the activesubstance is used up after 3 minutes' cleaning time. In multiple use,the active substance is, for example, used up after a typical period ofuse of 3 months, by which it is possible to indicate that the entirebrush should be replaced because of wear. An inscription (for example“Change”) can even be concealed under or in the active substance elementand becomes exposed after the active substance has been used up, suchthat it becomes visible to the user and draws the user's attention tothe imminent need to replace the active substance element or to therecommended replacement of the brush.

To increase the surface area that water washes around, the activesubstance element can be provided with additional recesses and concaveor convex elements on the surface.

The color of the active substance element is preferably chosen such thatit is clearly distinguished from the brush head and the user can easilyassess how much active substance has been used up.

The solubility or break-up of the active substance and of the carriermaterial depends on the water temperature used. The user can control therelease of the amount of active substance by regulating the watertemperature. With a temperature increase from 10° C. to 40° C., theamount of active substance released increases significantly.

In an advantageous development, the active substance is bound into aneffervescent tablet or into a paste with an effervescent action ascarrier material. This additional function allows the user to ascertain,during use, whether the active substance is already used up or is stillpresent in the cavity, without removing the brush from the mouth.

The brush is preferably packaged in such a way that the pack clearlyshows the consumer the brush and the active substance element. Theactive substance element is preferably positioned next to the brushhead. The active substance element is preferably provided in a part ofthe pack independent of the opening for the brush. In this way, theactive substance element remains hygienically closed until the intendedportion is opened. A first active substance element is preferablyalready positioned in the cavity of the brush head inside the retailpack. The brush head is positioned in the pack in such a way that theinsertion openings and outlet openings can be shown. This can be done inparticular using a so-called double blister pack, which allows the userto see both sides of the brush head. In addition to the purchase ofwhole brushes with active substance, it is also possible for just theactive substance element to be provided as a refill pack. As analternative design variant, the active substance in a suitable carriermaterial can also be provided in a dispenser for portioned delivery. Asan alternative to inserting the active substance element by hand, thebrush head in this design variant can be introduced into the dispenser,and the active substance can then be dispensed mechanically through theinsertion opening and into the cavity.

The cavity can be formed by the following injection-molding techniques:

-   (a) Variants with a one-piece brush head:-   (a1) Forming the cavity by means of mold cores/slides from the head    side supporting the bristles and/or from the rear face of the brush    head. In addition, and optionally, at least partial forced    de-molding of a deliberately undercut mold core for formation of a    membrane that delimits the cavity. To simplify its forced    de-molding, the membrane can be inflated by means of air pressure    through the mold core, thereby making damage-free de-molding easier.    Alternatively, the membrane can be deliberately slit in the area of    the insertion opening (e.g. mechanically in the mold tool by means    of slides/knives) which likewise promotes the de-molding of the    undercut mold core. Injection of optional cleaning and massaging    elements during production of the membrane.-   (a2) Like (a1), but forming of a cavity by means of mold    cores/lateral slides for formation of a tunnel extending    transversely through the brush head. Analogously, the    above-described forced de-molding can likewise be used for formation    of slits in the insertion opening.-   (a3) The cavity can be formed by means of over-injecting of the    active substance element. In this case, the active substance element    is fixed with a form-fit and force-fit on the hard component in the    head area and, in a further operating step, is at least partially    over-injected preferably with the soft component. In this    alternative production variant, the active substance element seals    the outlet openings in the hard component off from the soft    component. A disadvantage of this variant is that the active    substance and the carrier material have to withstand the high    temperatures and injection pressures of the soft component, and    water can only partially wash round them, because the soft component    bears directly on the active substance element in the over-injected    areas.-   (a4) As an alternative production variant, particularly in solutions    in which the active substance element is intended for multiple use,    the active substance element can be injected by means of injection    molding into the cavity or into a corresponding recess. For this    purpose, the active substances are preferably bound into a plastic    matrix as carrier material, which connects to the hard component of    the brush head in a subsequent injection-molding process. The brush    head, with the active substance injected on, can thus be produced in    a multi-component injection-molding technique. In one variant of the    invention, the carrier material is water-soluble and can also be    completely or partially dissolved during use. To produce the matrix    from the carrier material, use is made, for example, of substances    based on starch or other physiologically safe and degradable    substances that can be processed in injection-molding techniques,    for example cornstarch or Polyox®. Alternatively, use is made of a    plastic matrix which reacts to water, and in so doing releases    active substances, and which does not degrade but instead    substantially maintains its original geometry. This includes the    abovementioned hard or soft materials, to which the active substance    is admixed as an additive before or during the injection-molding    process. In this variant, it is advantageous if the active substance    element changes its color or at least fades as the active substance    is released, so as to show the user the ageing of the product. A    material is preferably used which connects to the hard component or    the soft component of the brush head. Since polypropylene PP is a    common hard material for producing toothbrushes, a carrier material    is preferably used which connects to PP. When using another hard    material for the brush head, a carrier material is used which    connects to this hard material during the injection-molding process.

Since suitable carrier materials can be relatively expensive compared tothe other materials used, it is proposed that the active substanceelement be injected on in the brush head or in the brush neck. Theinjection point is preferably situated on the rear face of the brushhead. In this embodiment variant, the active substance element isbrought by injection molding into a tablet shape or pill shape or intoanother above-described shape. The active substance element ispreferably arranged in a kind of sandwiched position between twomaterials used in the head, for example a hard material and a softmaterial, or two possibly identical hard materials. In this case, thehard material is advantageously first injected, then the activesubstance element is formed or injected, and then the active substanceelement is at least partially covered with the soft or hard material.Alternatively, the carrier material can also be a component part of thebristles or of any elastomeric cleaning and massaging elements, or thelatter can be coated with it. Of course, different active substanceelements with different active substances can also be formed on or inthe toothbrush head at different locations. A different color is thenadvantageously used for the different elements. With the production ofthe active substance element by means of injection molding, water canonly partially wash round the active substance element, but optimalundercuts can be formed for anchoring the active substance element.

-   (b) Variants with a multi-piece brush head:-   (b1) Conventional plugging or in-mold tufting (IMT) and cover:    Injection molding of the toothbrush including the half of the brush    head with the bristles, forming the outlet openings on the bristle    side and forming any cleaning elements from soft component—anchoring    the conventional bristles in the brush head—injection-molding the    rear half of the brush head (cover) including openings—releasable    connection (snap-fit, sliding fit, locking fit, etc.) or    non-releasable connection (adhesive bonding, welding, positive    locking, etc.) of the cover to the toothbrush.-   (b2) Provision of bristles by means of anchor-free tufting (AFT):    Injection molding of the toothbrush including the rear half of the    brush head and forming of the openings on the rear face of the brush    head—injection molding of the half with the bristles (bristle plate)    including openings and forming of any cleaning elements from soft    material—anchoring the conventional bristles in the bristle    plate—releasable connection (snap-fit, sliding fit, locking fit,    etc.) or non-releasable connection (adhesive bonding, welding,    positive locking, etc.) of the bristle plate to the toothbrush.-   (b3) The bristles are applied to a separate head plate; the cavity    is provided with the latter and with another preferably recloseable    cover (less preferred variant, since in three parts).

For all the variants discussed, it is possible for the active substanceand the carrier material to be introduced into the brush head in adifferent state of aggregation than in later use. The active substancecan, for example, be cast or injected into the cavity in liquid form(for example by heating or with addition of a solvent). After hardening,the active substance element is obtained which, during use with water,releases the corresponding active substances. The active substanceelement is preferably introduced into the cavity before the applicationof the cleaning elements, such as bristles, etc.

Any cleaning and massaging elements can be injected onto the membranebefore or after the insertion of the conventional bristles.

The slits for the insertion opening can be produced by the followingmethods:

-   (a) Formation of the segments and slits in the separate state by    means of injection molding,-   (b) Formation of a thin material bridge within the slits as a    tamper-evident safety means which can be severed by the user at the    time of the first use.-   (c) Formation of the membrane in the closed state. Creation of the    slits by means of a mechanical method (e.g. cutting, punching, etc.)    at a later stage (for example in the injection-molding tool, during    assembly of the brush head, or during the process of fitting the    bristles).

The injection points for the membranes, and for any cleaning ormassaging elements placed on the latter, are as far as possible to bechosen inside the head or in the neck area of the brush. Areas of softmaterial in the handle of the toothbrush can be produced in the sameoperating step and with the same material.

The cleaning or massaging elements arranged in the area of the membranesare preferably produced with the same material and in the same operatingstep with the membrane. By choosing a soft component with a Shore Ahardness of less than 70, preferably less than 40, a compromise can befound between the functionality of the membrane ((a) flexibility: pumpeffect, cleaning support, introduction of the active substance, (b)adherence to the hard material, etc,.)) and stiffness of the cleaning ormassaging elements (cleaning action, massaging action). The membranesmade from soft material are preferably bound to the hard component ofthe brush head in the multi-component injection molding technique. Toensure optimal adherence of the membrane to the hard component, caremust be taken to ensure that the membrane is not injected edge to edgeonto the hard component, and that a bevel/recess is instead provided inthe hard component to increase the common surface area between hardcomponent and soft component. For this purpose, a geometric element of0.1-2 mm depth/length is formed preferably over most of the join of themembrane to the hard component, in order to permit better binding of themembrane.

The first insertion of the active substance element into the brush headcan be done by the consumer at the first time of use, or it can be doneduring the production of the brush. With a two-part brush head, this canbe done especially by means of AFT. In the AFT method, the activesubstance element is positioned in the toothbrush head before thebristled AFT plate is welded non-releasably to the handle of thetoothbrush. The AFT method is generally recommended for positioning anadditional structural part or element between the bristled AFT plate andthe handle of the toothbrush.

Illustrative embodiments of the invention are described below and areshown purely schematically in the drawings, in which:

FIGS. 1-4 show different views of a head part of a toothbrush;

FIGS. 5-7 show different possibilities for forming the cavity in atoothbrush according to FIGS. 1-4;

FIGS. 8, 9 show different views of a head part of a toothbrush with aflexible bend zone;

FIGS. 10, 11 show different views of a head part of a toothbrush with aflexible zone which is circular in a plan view;

FIGS. 12, 13 show different views of a head part of a toothbrush with aflexible zone at the tip of the brush head;

FIGS. 14, 15 show different views of a head part of a toothbrush withseveral clusters of outlet openings;

FIGS. 16-21 show examples of different shapes of the flexible area in atoothbrush according to the invention;

FIGS. 22, 23 show different views of a head part of a toothbrush withoutlet openings on the rear face;

FIGS. 24-27 show examples of different shapes of the active substanceelement and of cavities adapted to the latter;

FIG. 28 shows a head part of a toothbrush with funnel-shaped outletopenings on the rear face;

FIG. 29 shows a toothbrush with a cavity in the neck area;

FIGS. 30-32 show different assembly methods for a toothbrush with acavity;

FIG. 33 shows a toothbrush with an active substance element that isencapsulated by injection molding upon production;

FIGS. 34, 35 show an example of a self-explanatory package for atoothbrush according to the invention;

FIG. 36 shows a household brush according to the invention.

In the drawings, elements with the same functions are in each caseprovided with the same reference numbers. FIGS. 1-4 show different viewsof a head area 10 of a toothbrush according to the invention. A cleaningstructure 12 composed of conventional bristles 14, gathered in bundles,and of pliable cleaning elements is applied to the front face 18.Instead of the conventional bristles 14, in some cases only theanchoring areas 38 of the bristle bundles are indicated. The head area10 is made from a hard component 30 which is solid (see also FIGS. 5-7)and in which in particular the conventional bristles 14 are anchoredwith a certain anchoring depth. Located within the hard component 30there is an aperture 31 which, in a plan view of the front face 18, hasa circular or elliptic shape and which is covered front and back by ineach case an outwardly curved flexible wall in the form of an elasticmembrane 28, 26 made of soft material 32. In this way, a cavity 22 isformed within the head area 10. The pliable structure 16 is anchored inthe membrane 28 on the front face. The membrane and the pliablestructure are preferably made together, in one production step, from thesame material and starting from the same injection point. The membrane26 on the rear face 20 has two intersecting slits which serve as arecloseable insertion opening 34 for an active substance element 24. Asis shown in the sectional drawings in FIGS. 5-7, the membrane 28 on thefront face has outlet openings 36 through which water can pass into thecavity 22 and can emerge again, this time enriched with activesubstance. The wall area of the cavity 22 is made from soft material 32and forms a flexible zone 29. Under the pressure exerted when cleaningthe teeth, the toothbrush deforms in this zone 29 in such a way thatwater is sucked into the cavity 22 and forced back out again.

Instead of a soft material, the membranes 26, 28 can also be producedfrom a hard component with suitably small wall thickness in order toachieve the necessary flexibility. However, the use of a soft componenthas advantages insofar as the anchoring of cleaning elements in a thinlayer of hard material is problematic from the production point of view,whereas the simultaneous injection of pliable elements onto a softmembrane does not cause problems. Alternatively, a combination of hardand soft materials can also form the membrane. In this case, theflexible elements of the membrane and cleaning elements are made fromsoft material. The hard component only forms structuring and stabilizingelements of the membrane, or it is used only as a material connectionrequired for production reasons.

As is shown in FIGS. 4-7, the cavity 22 is adapted to the shape of anactive substance element 24 in such a way that the latter is at leastpartially spaced apart from the inner wall 23 of the cavity 22. Topermit secure holding of the active substance element 24, projections oredges 40 are formed that extend inward from the flexible membranes 26,28 (FIGS. 5-7). The flexibility of the membranes 26, 28 means that theactive substance element 24 is well positioned, even as it continues tobreak up.

In the examples from FIGS. 6 and 7, an insertion opening 34, providedwith intersecting and mutually inclined closure flaps 42, additionallyensures that the active substance element 24 does not emerge again fromthe insertion opening under the effect of pressure when cleaning theteeth. The closure flaps 42 also serve as the abovementioned projections40.

In the examples according to FIGS. 1-7, the outlet openings 36 are ineach case located between the pliable cleaning elements 16 in themembrane 28 on the front face. The membrane surface thus has aperforated structure like a mesh.

FIGS. 8 and 9 show another example of a toothbrush composed of hard andsoft components 30, 32. Here, the soft component 32 forms a flexiblezone 29 which interconnects the two otherwise separate parts 10′, 10″ ofthe brush head 10 made from hard component 30. In contrast to the aboveexamples, the whole front part 10′ of the brush head can be deflectedrelative to the rear part 10″ of the brush head. As in the aboveexamples, the cavity 22 is delimited on the front and rear faces, andalso on the side, by thin material layers (membranes 26, 28) made fromsoft component 32, and, in the longitudinal direction, it is delimitedby the hard component 30. This configuration provides particularflexibility of the brush head 10 and an increased pump/suction effect inthe cavity 22. Alternatively, a connection piece made from hardcomponent 30 can also be guided through the inside of the soft component32, which allows the two parts 10′, 10″ of the brush head to be producedfrom hard component 30 in one operating step. This connection piece ispreferably made very thin in order to ensure that the flexibility is notnegatively affected. As in the above examples, it is mainly conventionalbristles 14 that are anchored in the hard component 30, whereas the softcomponent 32 is provided with pliable cleaning elements 16. Theinsertion opening 34 is designed as intersecting slits, as in FIGS. 1-7.

FIGS. 10 and 11 show an example which largely corresponds to FIGS. 1-7and in which the flexible zone 29 with the cavity 22 is not locatedcentrally within the bristle region, but is instead located more towardthe neck area 52. This has the advantage that the most extensivelyloaded zone in the front part of the brush head can be formed fromconventional bristles.

In FIGS. 12 and 13, the flexible zone 29 formed from soft material 32occupies the entire tip of the brush and has, in plan view, asubstantially circular shape. In a concentric arrangement, it heresupports, from the inside outward, pliable cleaning elements 16, outletopenings 36 and conventional bristles 14 (or their anchoring areas). Inthe direction of the neck area 52, it is adjoined by a region ofconventional bristles that is embedded in the hard component 30. Theoutlet openings 36 are large enough to allow the cavity 22 lying behindto be seen into.

In the example from FIGS. 14 and 15, although the part of the brush headmade from the hard component 30 is designed in one piece, it does haveapertures, with the result that a continuous flexible zone 29 on therear face 20 is formed with three areas (clusters) 44 of outlet openings36. These are located at the tip and on the sides of the head area 10,in each case in an outwardly curved flexible wall/membrane 28,preferably made of soft material 32. The remaining area of the head part10 is provided with conventional bristles 14 on the front face 18. Onthe rear face, there is once again an insertion opening 34 formed byintersecting slits, as in FIGS. 5-7.

FIGS. 16-21 show examples of different shapes of the flexible zone 29 ina toothbrush according to the invention, in a front view and rear view(FIGS. 16-19), and only in a front view (FIGS. 20 and 21). In all theexamples, the rear face once again is provided with an insertion opening34 formed by intersecting slits, as in FIGS. 5-7 (only shown in some).In FIGS. 16 and 17, the flexible zone 29 has three laterally arranged,gill-like areas 46 (or clusters 44) with lamella-like cleaning/massagingelements 16 and with outlet openings 36 arranged between them. The areas46 are interconnected on the rear face by a material bridge of softmaterial 32 (see FIG. 17). In FIGS. 18 and 19, the lamellas/gills areless pronounced, and only two lateral clusters 44 are present. FIG. 20shows a modification of this, with an asymmetrically curved geometry. InFIG. 21, the outlet openings 36 are distributed uniformly over thelateral edge of the head area 10 and are each surrounded by knobs ofsoft material, such that a massaging effect is also provided here by theknobs during cleaning of the teeth.

FIGS. 22 and 23 show a brush in a front view and rear view, where theoutlet openings 36 are located on the rear face 20 directed away fromthe bristles and, therefore, the active substance is essentiallyreleased on the rear face 20. The rear face 20 is largely made of hardmaterial 30 which is perforated like a mesh and allows a view of thecavity 22 inside the brush head 10. The cavity 22 extends substantiallyover the whole surface of the head part 10. The sufficient flexibilityof the wall of the cavity 22 is achieved by a suitably small materialthickness and by the perforations or outlet openings 36. Part of thecavity 22 is covered on the rear face by a membrane 26 of soft material32 in which slits, arranged in a star shape, serve as insertion opening34.

In the example shown in FIG. 24, the brush head 10 is composed of twoparts (the tip 10′, and the area 10″ toward the neck) which are madefrom a hard component 30 and which are connected to one another by aflexible zone 29 made from soft material 32 or from a combination ofhard and soft material. A cavity 22 in the shape of a tubular recesswith an elliptical cross section is formed in the flexible zone 29. Thecavity 22 is delimited toward the front face 18 by three webs of softmaterial 32. Located between the webs 48 there are two outlet openings36 with a total width of about half the width of the head. The undersideof the cavity 22 is made completely from soft material 32 or from acombination of hard and soft material. Pliable cleaning elements 16 arearranged on the webs 48, while conventional bristles 14 are anchored onthe hard areas at the tip and in the area toward the neck. An ellipticalinsertion opening 34 for the active substance element 24 is formedbetween the webs 48 and the underside 66 of the cavity 22. The activesubstance element 24 has basically the shape of a cylinder with anelliptical cross section and rounded edges. The active substance element24 is clamped between the webs and the underside 66. However, at thesides, it is spaced apart from the inner wall of the cavity 22, suchthat water washes round it there and in the area of the outlet openings36. By virtue of the spatial configuration with a substantially two-parthard component 30 and a flexible zone 29 of soft material 32 connectingthe parts, the brush head is particularly flexible. Alternatively, thewebs 48 can likewise be made from the hard component 30 and can form ahinge-like connection between the tip and the area toward the neck; theflexibility is in this case ensured by the webs 48 having a suitablythin wall.

FIGS. 25-27 show modifications of the example from FIG. 24, again with asubstantially two-part head area 10 made from a hard component 30 andwith a flexible zone 29 which connects the parts 10′, 10″ and is madefrom soft component 32 or from a combination of hard and soft component,and in which the cavity 22 for receiving the active substance element 24is accommodated. In FIGS. 25 and 26, the cavity 22 and the activesubstance element 24 itself are cylindrical with a circular crosssection. The insertion opening 34 is likewise circular and can have asmaller diameter than the cavity 22 itself, such that water can wash atleast partially round the active substance element 24 in the cavity 22.In the direction radial to its longitudinal direction, the cavity 22 issubstantially surrounded by soft material 32, except for the outletopenings 36 in the membrane 28 on the front face. In the case of FIG.25, pliable, tubular cleaning elements are formed integrally onto themembrane 28, the interior of these cleaning elements 16 communicatingwith the cavity 22 in such a way that dissolved active substance is alsoreleased via outlet openings 36′ at the upper end of the cleaningelements 16. The release of active substance is intensified by thecapillary effect. In the case of FIG. 26, no pliable cleaning elementsare arranged on the soft component.

FIG. 27 shows an analogous example with an elastic zone 29 which islengthened in the longitudinal direction of the brush head and in whicha substantially cuboid cavity 22 is formed. The latter is adapted to aplate-shaped or film-shaped active substance element 24. In thisembodiment variant, the plate-shaped or film-shaped cavity 22 can beapplied as a rucksack-shaped structure on the rear face of the brushhead. The active substance element 24 has a thickness of 0.01 to 5.0 mm,preferably of 0.05 to 1.0 mm.

In all the examples in FIGS. 24-27, in order to form the tunnel-likecavity for the active substance element, a suitable lateral slide isfitted in the injection-molding tool for the injection molding of thehard and/or soft component.

In the example from FIG. 28, the cavity 22 is covered on the rear face20 of the brush head by a flexible membrane 26 of soft material 32 andis otherwise formed within the hard component 30. The outlet openings 36on the membrane 26 are formed in knob-like or funnel-like elevationsthat can at the same time act as cleaning or massaging elements 16, inparticular for the palate and the tongue. The front face 18 made fromthe hard component 30 can thus also be provided conventionally withbristles outside the cavity 22. A combination of this embodiment with apreviously shown flexible membrane on the front face of the brush headis also conceivable. The movement of the knobs during cleaning of theteeth means that water is sucked into the cavity and, enriched withactive substance, is ejected again.

FIG. 29 shows a toothbrush in which the cavity 22 is formed by acage-like thickening which is provided in the neck area 52 and which isadapted to a spherical or ellipsoid shape of the active substanceelement. It has a multiplicity of outlet openings 36 through which thecavity 22 can be seen. The boundary of the cavity can be formed fromhard and/or soft component, and, in the latter case, a damping zone isobtained in the neck area 52. The flexibility of this zone promotes thepump effect around the active substance element, which effect isdiscussed in more detail above.

FIGS. 30-33 are schematic representations of different productionmethods for brushes according to the invention. These production methodscan of course be employed for all the embodiment variants shown.

In FIG. 30, the toothbrush, composed of two parts, is produced from hardand/or soft component 30 in the injection-molding technique,specifically, on the one hand, the upper half of the brush head providedwith the bristles, and, on the other hand, the cover 54 on the rearface. A recess for the active substance element 24 is formed in theupper half, and this recess is later closed by the cover 54 to form thecavity 22. On the upper half, the outlet openings 36 and, ifappropriate, the cleaning elements 16 are formed from soft component 32.Conventional bristles are anchored, laterally of the cleaning elements16, by conventional plugging or in-mold tufting (IMT). Further outletopenings 36 are formed in the hard component 30 on the cover 54.Alternatively, the cover 54 can also contain a membrane made from softcomponent, in which the outlet openings are formed in knob-likeelevations. The cover 54 and the rest of the brush head are thenconnected, with inclusion of a flat active substance element 24, eitherreleasably (snap-fit, sliding fit, locking fit, etc.) or non-releasably(adhesive bonding, welding, positive locking, etc.).

In FIG. 31, the toothbrush is likewise produced as two parts from a hardand/or soft component in the injection-molding technique. The half ofthe brush head forming its rear face has a saucer-shaped depressionwhich, upon connection to a support plate 56, forms a cavity 22. Thesupport plate is produced including openings which, in a furtherinjection-molding step, are closed with soft component 32 to form amembrane 26 and possibly also with pliable cleaning elements 16 madefrom soft component. The conventional bristles 14 are then anchored inthe support plate 56. Alternatively, the support plate 56 can also beprovided with bristles by the anchor-free tufting method, which has theadvantage that the support plate can be made thinner. The support plateis then connected to the rest of the toothbrush either releasably(snap-fit, sliding fit, locking fit, etc.) or non-releasably (adhesivebonding, welding, positive locking, etc.), with an active substanceelement 24 being enclosed in the cavity 22.

FIG. 32 shows a combination of the examples from FIGS. 30 and 31, with abrush head composed of three parts (annular body, support plate 56 andrear cover 54).

FIG. 33 shows a further example in which, during the production of thetoothbrush, the active substance is inserted or injected into a recessin the hard component 30, and the soft component 32 is injected over it.By doing so, a cavity 22 with a flexible wall in the form of a thinmembrane 28 made from soft component 32 is formed. The membrane 28 isprovided with openings 36 for the entry and exit of water or of activesubstance dissolved in water.

In all the examples, the flexibility of the wall of the cavity 22 isachieved through the choice of a wall material having a certainelasticity, particularly by at least one membrane made of soft material32 being present, and/or through the existing overall flexuralelasticity of the brush made of hard and/or soft material. As long assufficient contact with water is guaranteed, or sufficient dissolving ofthe active substance, it suffices if the pump/suction effect, or thechange in volume of the cavity due to the cleaning pressure, is onlyslight or is even non-existent.

FIGS. 34 and 35 show a self-explanatory package 58 for a toothbrush withactive substance, which package 58, in addition to having a recess 60adapted to the brush shape, also comprises a detachable area with anactive substance element 24. The user therefore sees immediately whatproduct it is.

The embodiment variants described above can of course also be used onelectric toothbrushes. The mechanical movement or vibration of at leastpart of the brush head additionally favors the exchange of liquid intoand out of the cavity. If the brush head is divided into a movablebrush-head segment and a non-movable brush-head segment, the cavity, inthe above-described variants, is preferably accommodated in thenon-movable segment.

FIG. 36 shows a household brush, also with a head part, neck part andhandle part 10, 52, 62. In the head area there is a cavity 22 which, onthe face directed away from the cleaning structure 12, can be reclosedby a flap 64 and can receive an active substance element 24. The outletopenings for the dissolved active substance are located in the flap 64.In the washing-up brush, a solid soap is preferably inserted as theactive substance element. All the embodiment variants described abovecan be applied analogously to the washing-up brush. The stateddimensions are to be adapted to the dimensions of the brush head.

Combinations of elements from the examples shown also come within thescope of the invention.

A brush with a flexible membrane which is provided in the head part, andwhich supports cleaning and/or massaging elements, has advantages evenwithout a cavity situated below it, and even without an active substanceelement inserted in the cavity, particularly because of the flexiblesuspension of the cleaning and/or massaging elements. All the examplesshown can be accordingly modified, for example by no cavity beingprovided, or by providing a cavity that does not communicate with theoutside. For this purpose, the examples shown in FIGS. 1-27 areparticularly suitable, in which the flexible zone 29 is retained but hasno function in terms of the admission and release of active substance.

The invention claimed is:
 1. A toothbrush comprising a head part, a neckpart, a handle part, a cavity or a corresponding recess and an activesubstance element, the head part being made from a hard material and asoft material and comprising a rear half and a front half, the rear halfof the head part being integrally formed with the handle part, the rearhalf and the handle part comprising the hard material, the front half ofthe head part having a cleaning structure comprising bristles and abristle carrying head plate, said bristle carrying head plate comprisingthe hard material, wherein the cavity or the recess is located in thehead part and is defined by the rear half of the head part and by thebristle carrying head plate, the cavity or the recess comprises at leastone outlet opening for the active substance element, the activesubstance element is arranged in the cavity or the recess and is in aform of a solid body, and at least the rear half of the head part or thebristle carrying head plate are provided with an additional softmaterial structure.
 2. The toothbrush as claimed in claim 1, wherein theactive substance element contains the active substance in a carriermaterial, and the carrier material releases the active substance uponcontact with water, the carrier material being an injection-moldablepolymer.
 3. The toothbrush as claimed in claim 2, wherein theinjection-moldable polymer is water-soluble.
 4. The toothbrush asclaimed in claim 2, wherein the carrier material is a plastic which,during injection into the recess of the head part, connects to a plasticmaterial of the head part.
 5. The toothbrush as claimed in claim 1,wherein the active substance element contains flavoring agents and/orantibacterial substances and/or abrasive substances as the activesubstance.
 6. The toothbrush as claimed in claim 1, wherein the activesubstance element contains an indicator, such that the active substanceelement changes color or fades as a period of use advances.
 7. Thetoothbrush as claimed in claim 1, wherein the active substance elementhas a period of use of 3 months and, when the active substance is usedup, a need to replace the toothbrush is indicated.
 8. The toothbrush asclaimed in claim 1, wherein, an inner wall of the cavity has projectionsor other geometric elements that position the inserted active substanceelement in the cavity by clamping the active substance element.
 9. Thetoothbrush as claimed in claim 1, wherein the cavity is at leastpartially delimited by soft material.
 10. The toothbrush as claimed inclaim 1, wherein the cavity is at least partially delimited by aflexible membrane comprising a soft material that curves at leastpartially outward.
 11. The toothbrush as claimed in claim 10, whereinthe flexible membrane comprises a soft material that has a Shore Ahardness of less than
 70. 12. The toothbrush as claimed in claim 10,wherein massaging and/or cleaning elements, comprising soft material,are arranged on the head part and are produced along with the flexiblemembrane in one operating step and from the same material.
 13. Thetoothbrush as claimed in claim 12, wherein the at least one outletopening is situated in the flexible membrane between the massagingand/or cleaning elements and/or in the massaging and/or cleaningelements.
 14. The toothbrush as claimed in claim 1, wherein the at leastone outlet opening is situated in the hard and/or soft material of thehead part.
 15. The toothbrush as claimed in claim 1, wherein the atleast one outlet opening is formed as a flat perforated structure, aconcertina-like structure, a lamella-like structure and/or a knob-likestructure and is arranged on the rear face of the head part.
 16. Thetoothbrush as claimed in claim 1, wherein the at least one outletopening is formed as a knob-like structure and is arranged on the frontface of the head part.
 17. A toothbrush comprising a head part, a neckpart, a handle part, a cavity or a corresponding recess and an activesubstance element, the head part being made from a hard material and asoft material and comprising a rear half and a front half, the rear halfof the head part comprising the hard material and being provided with aCover, the front half of the head part being integrally formed with thehandle part, the front half and the handle part comprising the hardmaterial and being provided with a cleaning structure that comprisesbristles, wherein the cavity or the recess is located in the head partand is defined by the front half of the head part and by the cover, thecavity or the recess comprises at least one outlet opening for theactive substance element, the active substance element is arranged inthe cavity or the recess and is in a form of a solid body, and at leastthe front half of the head part or the cover are provided with anadditional soft material structure.
 18. The toothbrush as claimed inclaim 17, wherein the active substance element contains the activesubstance in a carrier material, and the carrier material releases theactive substance upon contact with water, the carrier material being aninjectionmoldable polymer.
 19. The toothbrush as claimed in claim 18,wherein the injection-moldable polymer is water-soluble.
 20. Thetoothbrush as claimed in claim 18, wherein the carrier material is aplastic which, during injection into the recess of the head part,connects to a plastic material of the head part.
 21. The toothbrush asclaimed in claim 17, wherein the active substance element containsflavoring agents and/or antibacterial substances and/or abrasivesubstances as the active substance.
 22. The toothbrush as claimed inclaim 17, wherein the cavity is at least partially delimited by softmaterial.
 23. The toothbrush as claimed in claim 17, wherein the cavityis at least partially delimited by a flexible membrane comprising softmaterial that curves at least partially outward.
 24. The toothbrush asclaimed in claim 23, wherein the flexible membrane comprises a softmaterial that has a Shore A hardness of less than
 70. 25. The toothbrushas claimed in claim 23, wherein massaging and/or cleaning elements,comprising soft material, are arranged on the head part and are producedalong with the flexible membrane in one operating step and from the samematerial.
 26. The toothbrush as claimed in claim 25, wherein the atleast one outlet opening is situated in the flexible membrane betweenthe massaging and/or cleaning elements and/or in the massaging and/orcleaning elements.
 27. The toothbrush as claimed in claim 17, whereinthe at least one outlet opening is situated in the hard and/or softmaterial of the head part.
 28. The toothbrush as claimed in claim 17,wherein the at least one outlet opening is formed as a flat perforatedstructure, a concertina-like structure, a lamella-like structure and/ora knob-like structure and is arranged on the rear face of the head part.29. The toothbrush as claimed in claim 17, wherein the at least oneoutlet opening is formed as a knob-like structure and is arranged on thefront face of the head part.
 30. A toothbrush comprising a head part, aneck part, a handle part, a cavity or a corresponding recess and anactive substance element, the head part being made from a hard materialand a soft material, the head part comprising a rear half, a front halfand an annular body, said annular body being integrally formed with thehandle part, the annular body and the handle part comprising a hardmaterial, the rear half of the head part comprising the hard materialand being provided with a cover, which comprises the hard material, thefront half of the head part having a cleaning structure comprisingbristles and a bristle carrying head plate, said bristle carrying headplate comprising the hard material, wherein the cavity or the recess islocated in the head part and is defined by the annular body of the headpart, by the bristle carrying head plate and by the cover, the cavity orthe recess comprises at least one outlet opening for the activesubstance element, the active substance element is arranged in thecavity or the recess and is in a form of a solid body, and at least thebristle carrying head plate or the cover are provided with an additionalsoft material structure.
 31. The toothbrush as claimed in claim 17,wherein the solid body is shaped as a tablet, pill, rod-shaped element,plate or film to match the cavity or the recess.
 32. The toothbrush asclaimed in claim 1, wherein the solid body is shaped as a tablet, pill,rod-shaped element, plate or film to match the cavity or the recess.